1. Field of the Invention
The present invention relates to a board conveying hand for adsorptively holding a board and a board conveying device provided with the same.
2. Discussion of the Background
A board conveying device has been utilized in conveying a thin board such as glass or a semiconductor wafer for use in fabricating a liquid crystal display, a plasma display, a semiconductor, and the like. The board conveying device is frequently used in taking out a board housed inside of a cassette to deliver it to a board processing device or receiving a board from a board processing device to house it inside of a cassette. Most of the board conveying devices to be used in such a manner is provided with a board conveying hand for mounting a board thereon while conveying it (see, for example, Japanese Patent Application Laid-open No. 2007-83322).
The board conveying hand includes a plurality of rod-like forks with respect to a support member, the forks mounting a board thereon. Each of the forks has an adsorbent for preventing the board from being shifted when it is conveyed. The adsorbent adsorptively holds the board. In the board conveying device, for example, the forks are inserted inside of the cassette, and then, the board is adsorptively held by the adsorbents formed on the forks, to be thus conveyed to a desired destination in a board processing device or the like.
On the other hand, a pitch between the boards inside of the cassette (i.e., a clearance between the boards) has been reduced in order to increase board mountability inside of the cassette for the purpose of enhancement of productivity. Similarly, the board has become larger for the purpose of enhancement of productivity, with an attendant problem that the board is liable to be flexibly deformed. Worse still, as the board has become larger, the fork need be formed into a long rod, so that when the board conveying hand is actuated by the board conveying device, the tip of the fork, in particular, is liable to be largely vibrated. As a consequence, since the fork of the board conveying hand hardly intrudes into the cassette, various ideas have been designed such that the thickness of the fork is reduced while the rigidity of the fork is enhanced so that the vibration is suppressed.